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This problem wouldn't occur nearly so often if staff would stick to disconnecting from the mains by unplugging the mains plug from the wall socket instead of pulling the IEC plug out of the unit's IEC socket.

Alternately they could as a point of self protection turn the wall socket off, then unplug the IEC if they feel absolutely compelled to do so.

In any case leaving live IEC leads dangling around the place is in itself dangerous. There was even a few instances a few years back of staff taking a dangling live IEC plug and mistaking it for a patient cable, plugging ECG monitor flying leads into the IEC lead holes and shocking the patients.

Disconnecting an IEC connector while live is an inherently bad idea because of the arcing that occurs as contact is broken. It doesn't do any good to the IEC contacts and can't be much good for the medical devices power supply either.

Marc

...but it happens in every NHS hospital a thousand times a day! It also defeats the validity of all that recording of electrical safety tests, need I add? So much wasted time, then.

Bring back HTM-8 and fixed mains leads, says I. So much, then, for "progress". I urge all equipment manufacturers to “design down for dumb”!

We had an incident with Haemonetics Cell Saver,switched the unit off disconnected from the mains and a charge remained on the L-N pins on the plug,this was repeatable and measured on an oscilloscope. Reported to the MHRA and the company. Finally the unit was modified by the company (this took a while as they had to get CE approval on the modification)and a reccommendation from MHRA to BSI to tighten up the regulation of on the mains input filter circuitry. The problem lies with the value of capacitor allowed across the L-N terminals and L-E and N-E terminals. I Will have to look at IEC601 and what the values were in this instance to comment further.

I was looking at a mock up the bed area of a new wing being built when I was at GOSH and commented on the lack of switches on the mains plugs. I said that for years I had been saying turn off at the wall before unplugging. (I have known two cases of staff having a shock from broken mais plugs pulled out whilst turned on.)
But the new regulations say that sockets that might have medical devices plugged in them must not have a switch so that the batteries of the equipment will be charged up.
I look forward to more staff injuries in the future. At least you could isolate a swinging IEC lead in the past.
Robert

Are the new regulations issued as part of a HTM from NHS Estates?

I believe so. But I cannot quote a number.
Robert

After the invention and introduction of ELCB(Earth Leakage circuit Breaker) in the LT power supply distribution, this kind of regulation, they might have passed.
I have also seen in United states, in all health care units and residences, there is no isolating switch combined in the wall outlets.
But in my personnel opinion, there must be a isolating switch which also to be mechanically inter locked with plug top. I mean that the power plug can not be removed with out switching off the power supply. This kind of arrangements have to be done atleast, in Hospital grade power plugs.

Good idea but not actually practical if you are dealing with standard plugs and sockets. I do not think we can alter these as it would have to happen for a whole hospital in one hit. All the equipment in use would have to have its plug changed along with all the sockets, all at the same time.
I have asked about RCDs(ELCBs as they used to be called) and it was pointed out that you would need one per socket. If a group of sockets were to be on one trip a faulty piece of equipment might take out a vital (non-faulty) bit of equipment which would not ne acceptable. And providing an RCD for each outlet would prove far too costly.

As for US plugs not having switches, the whole system of electicity distribution within buildings makes most Europeans cringe. They think that as they have a lower safer voltage they can get away with things Europeans would consider dangerous. I have seen outlets in a bathroom in the direct line of fire of a shower and light switches next to a sink. Though some would say the Europeans are too safety conscious.
I would be careful as using the US as an example of "good" or "standard" electrical safety. Why do they need special "Hospital Grade" plugs? Is it because their standard ones are no good?
Robert